1. Field of the Invention
The present invention relates generally to telephony, and more particularly to allowing a caller to initiate call overflow in a telecommunications network.
2. Related Art
The proliferation of virtual private networks, such as MCI VNET, has introduced many new functions for telecommunications networks. One such function is known as "call overflow." In a conventional implementation, call overflow causes a call to a particular terminating location to be redirected to a predetermined overflow location under certain conditions, referred to herein as "overflow conditions." Overflow conditions can include abnormal call termination, expiration of a timer, certain busy conditions, and the like.
FIG. 1 depicts a portion of a typical telecommunications network 100. Telecommunications network 100 includes a data access point (DAP) 102, a switch 104, originating call location O, terminating call locations T1 and T2, and trunk groups TG0, TG1, and TG2. FIG. 2 is a flowchart depicting the operation of a conventional call overflow system. In the following example, terminating location T1 subscribes to a conventional call overflow function provided by telecommunications network 100.
Referring to FIG. 2, a caller at call origination location O initiates a call to terminating location T1, as shown in step 202. When switch 104 receives the call, it queries DAP 102 for routing information for the call, as shown in a step 204. DAP 102 consults the call processing plan for terminating location T1. Because terminating location T1 subscribes to the call overflow function, the call processing plan indicates that call overflow is available. Therefore, as shown in step 206, DAP 102 determines that call overflow is available for terminating location T1. In addition, DAP 102 determines the call routing for the call to reach terminating location T1.
DAP 102 sends the call routing information, and a call overflow available indication, to switch 104, as shown in step 208. Switch 104 then routes the call to terminating location T1, as shown in step 210. If an overflow condition occurs, as shown in step 212, then call overflow is performed, as shown in step 220. Typically call overflow processing includes transferring the call to another terminating location. Assume in this example that the call processing plan for terminating location T1 specifies terminating location T2 as the overflow call terminating location. In this example, call overflow processing includes transferring the call from terminating location T1 to terminating location T2.
A primary disadvantage of such conventional implementations is that the caller has no control over the call overflow process. In such an implementation, the caller can only wait for an overflow condition to occur, thereby triggering call overflow processing. In many instances, this wait is considerable. Such long wait times result in increased telephone service costs, inconvenience to the caller, the perception by callers of poor service, and the loss of calls and the business associated with those calls.